In case that a channel status between an eNode B and a user equipment, a relay node (RN) is installed between the eNode B and the user equipment, thereby providing the user equipment with a radio channel having a better channel status. Moreover, by introducing a relay node into a cell edge area having a poor channel status from an eNode B, if the relay node is used, it may provide a faster data channel and extend a cell service area. Thus, a relay node is the technology introduced to solve the propagation shadow zone problem of a wireless communication system and is widely used.
Compared to a conventional relay node having a function limited to a function of a repeater configured to simply amplify and transmit a signal, a recent relay node is evolved into a further-intelligent form. Moreover, the relay node technology corresponds to the technology essential to service coverage extension and data throughput improvement as well as cost reductions for base station expansion and backhaul network maintenance in a next generation mobile communication system. To keep up with the ongoing development of the relay node technology, it is necessary for a new wireless communication system to support a relay node used by the related art wireless communication system.
At least one or more cells exist in a single base station (or eNode B). The cell sets a single carrier to one of bandwidths including 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz and the like and then provides DL/UL (downlink/uplink) service to a plurality of user equipments. In doing so, different cells may be configured to provide different bandwidths, respectively. A base station (or eNode B) transmits downlink (DL) scheduling information for downlink (DL) data to inform a corresponding user equipment of time/frequency region for transmitting data, coding, data size, HARQ (hybrid automatic repeat and request) related information and the like. The base station also transmits UL scheduling information for uplink (UL) data to the corresponding user equipment to indicate time/frequency region available for the corresponding user equipment, coding, data size, HARQ related information and the like. Moreover, an interface for user or control traffic transmission may be usable between base stations (or eNode Bs).
Wireless communication technology has been developed up to LTE based on WCDMA (wideband code division multiple access). Yet, the demand and expectation of users and service providers has increased persistently. Moreover since many ongoing efforts are made to research and develop other radio access technologies, the demand for new technology evolution is increasing to have competitive power in the future. In particular, cost reduction per bit, service availability expansion, flexible frequency band use, simple-structured open interface, reasonable power consumption of user equipment and the like are required.
Recently, ongoing standardization of the next technology of LTE is performed by 3GPP. Such technology shall be named LTE-A. Big differences between LTE system and LTE-A system may include a system bandwidth difference and an adoption of a relay node.
The goal of LTE-A system is to support maximum 100 MZ wideband. To this end, LTE-A system uses carrier aggregation or bandwidth aggregation to achieve the wideband using a plurality of frequency blocks. According to the carrier aggregation, a plurality of frequency blocks are used as one wide logical frequency band to use wider frequency band. And, a bandwidth of each frequency block may be defined based on a bandwidth of a system block used by LTE system. And, each frequency block is transmitted using a component carrier.